The History of New York City Water

pepactonArun Ravindranath has published his work on the history of New York City Water supply and the Delaware River Basin Compacts in Water Policy Journal. His work is focused on understanding water risks and how the reservoir systems perform under changing climate and political and institutional constraints. He is developing a framework to assess the dynamics of natural and human systems to inform water allocations and policy. We welcome any comments. Here is a quick summary of the work.

The Delaware River is the longest continuous river in the Eastern United States. The river basin encompasses four states, New York, New Jersey, Pennsylvania and Delaware, covers roughly 13,000 square miles, and supplies more than 15 million people with water for drinking, agriculture and industrial use. The Delaware water release policies are constrained by the dictates of two U.S. Supreme Court Decrees, 1931 and 1954, and the need for unanimity among four states and New York City. Critical stakeholder groups include New York City, a variety of environmental interests, and key water organizations from the four states. The reliance of several entities on upstream water sources has led to competing interests, conflicts, and disputes over the years. Arun, through this investigation, has explored important changes in the allocation rules, key implementation issues surrounding drinking water supply and environmental impacts on the downstream ecosystem, wildlife, and fisheries, and provided context for social value changes.

Image - courtesy of

Learning from River’s History

Recently, I spoke to Lakis Polycarpou from Columbia University about my trip to
Bozeman, MT for an NSF project meeting on Paleo reconstruction of river discharges using tree rings for the Missouri River basin. Reconstruction of discharge from tree rings spanning past several centuries can provide a more complete picture of the range of variability (the deviation from average conditions) of the flows in the river at decadal to longer time scales. This proxy information (long history of flows) can be used to evaluate how good the current water policies are in the context of history. Here is the link to his article on our discussion. is a very useful resource on tree rings, climate and water management.

For the more modeling-saavy, you can read my article on streamflow reconstruction using tree rings for the New York City reservoirs.






Source for the tree photograph: Dear friend Uday Maripalli’s Instagram.